JP2763898B2 - Shield plate for magnetic head and method of manufacturing the same - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield plate for a magnetic head and a method of manufacturing the same, and more particularly, to a magnetic head in which a plurality of head elements each including a magnetic core and a coil are arranged in parallel. The present invention relates to a magnetic head shield plate which is disposed between matching head elements and performs magnetic shielding between head elements, and a method of manufacturing the same.

[Prior Art] The conventional structure of this type of shield plate for a magnetic head is the third one.
It is as shown in the figure.

That is, the magnetic head shield plate includes a magnetic metal plate (permalloy, etc.) 1 and a non-magnetic metal plate (copper, etc.) 3, each having a shape shown in FIG. 3 ′, a non-magnetic metal plate 3, 3 ′ is laminated on both sides of the magnetic metal plate 1, and an adhesive
5, 5 '.

In the manufacturing process of the shield plate, first, the magnetic metal plate 1 and the non-magnetic metal plates 3, 3 'are press-cut from their respective base metal strips into the illustrated shape corresponding to the shape of the magnetic core of the magnetic head (not shown). I do. Next, the adhesive 5,5 'is applied to the non-magnetic metal plate 3,3'.
Then, the non-magnetic metal plates 3, 3 'and the magnetic metal plate 1 are laminated and joined.

On the other hand, as another conventional structure of a shield plate for a magnetic head, a cylindrical bottomed boss is formed on a magnetic metal plate by half blanking, and a hole is formed in a portion corresponding to the boss on a nonmagnetic metal plate. A structure is adopted in which a magnetic metal plate and a non-magnetic metal plate are joined by press-fitting the boss into the hole.

[Problems to be Solved by the Invention] However, in the conventional structure shown in FIG. 3, a man-hour is required for a bonding process between a magnetic metal plate and a non-magnetic metal plate in a manufacturing process, and the cost is increased. The thickness of the magnetic metal plate and non-magnetic metal plate is
Since it is as thin as 0.1 mm or less, a defect such as bending occurs due to handling during the work of the bonding step, and the yield of the shield plate deteriorates. Further, when the magnetic metal plate and the non-magnetic metal plate are laminated, there is a problem that misalignment of each metal plate easily occurs and it is difficult to obtain dimensional accuracy of the shield plate.

On the other hand, in the structure in which the magnetic metal plate and the non-magnetic metal plate are joined by press-fitting the boss and the hole, all the steps of the manufacturing process of the shield plate can be performed consistently by pressing, and the above-described problem does not occur. However, since a large joining strength cannot be obtained by joining by press-fitting the boss and the hole, there is a problem that defects such as peeling of the metal plate easily occur in the finished shield plate.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a magnetic head shield plate and a method of manufacturing the same, which can manufacture the magnetic head shield plate at low cost and high yield with high productivity, and have high dimensional accuracy and sufficient metal plates. An object of the present invention is to provide a structure of a shield plate for a magnetic head capable of obtaining the bonding strength described above and a method for manufacturing the same.

According to the present invention, there is provided a magnetic head shield plate formed by laminating and joining a plurality of metal plates each having a predetermined shape, and a method of manufacturing the same. In at least one metal plate among the plurality of metal plates, a bottomless cylindrical convex portion longer than the thickness of the other metal plate is formed by burring, and the other metal plate has the convex portion. A hole was formed in a portion corresponding to the above, and the metal plate was joined together by inserting the convex portion into the hole and caulking the peripheral portion of the hole.

[Operation] According to such a configuration, all steps of the manufacturing process of the shield plate can be performed consistently by pressing, and the shield plate can be manufactured with high productivity and high dimensional accuracy. In addition, according to the method of joining metal plates by crimping the protrusions, a significantly higher joining strength can be obtained than the conventional joining method by press-fitting the protrusions.

EXAMPLES Hereinafter, the details of the present invention will be described based on examples shown in the drawings.

FIG. 1 and FIG. 2 are an exploded perspective view and a perspective view of a finished product for explaining a structure and a manufacturing method of a shield plate for a magnetic head according to an embodiment of the present invention.

In both figures, reference numeral 1 denotes a magnetic metal plate (such as permalloy), and reference numerals 3 and 3 'denote nonmagnetic metal plates (such as copper), each of which has a shape shown corresponding to the shape of a magnetic core of a magnetic head (not shown). Is formed.

Non-magnetic metal plates 3, 3 'are laminated on both sides of magnetic metal plate 1,
By joining, a shield plate for a magnetic head is formed.

For joining the magnetic metal plate 1 and the non-magnetic metal plates 3, 3 ',
The magnetic metal plate 1 has four protrusions 2a to 2d formed at four corners. Each of the projections 2a to 2d is formed in a bottomless cylindrical shape, that is, a cylindrical shape whose both ends are open, and has a length sufficiently longer than the thickness of the nonmagnetic metal plates 3, 3 '. Of the protrusions 2a to 2d, the protrusions 2a and 2d protrude leftward in the drawing of the magnetic metal plate 1, and the protrusions 2b and 2c protrude rightward.

The projections 2a to 2d are formed by a burring process using a press, that is, a process in which a hole is formed by a press and a hole is formed so that a cylindrical burr is formed at the edge of the hole.

On the other hand, the protrusions 2a and 2d of the magnetic metal plate 1
Holes 4a and 4d are formed in each of the portions corresponding to. Holes 4b and 4c are formed in the nonmagnetic metal plate 3 'at portions corresponding to the protrusions 2b and 2c, respectively. Holes 4a-4d
Are circular in this case corresponding to the convex portions 2a to 2d, and the diameters thereof correspond to the diameters of the convex portions 2a to 2d.
2d is fitted and made large enough to be inserted.

Under such a structure, the non-magnetic metal plates 3, 3 'are laminated on both sides of the magnetic metal plate 1 as shown by arrows in FIG. 1, and at this time, the projections 2a to 2d are formed in the holes 4a to 4d. Each is fitted and inserted. Then, the portions of the projections 2a to 2d projecting from the holes 4a to 4d are caulked against the peripheral portions of the holes 4a to 4b by pressing, that is, the projections of the projections 2a to 2d are expanded as shown in FIG. The non-magnetic metal plates 3, 3 'are joined to the magnetic metal plate 1 by being pressed into close contact with the peripheral edges of the holes 4a to 4d, thereby forming a magnetic head shield plate.

In the manufacturing process of such a shield plate, first, the magnetic metal plate 1 is press-cut from the base material band, and then the convex portions 2a to 2d are formed on the magnetic metal plate 1 by burring of the press described above. Further, the nonmagnetic metal plates 3, 3 'are pressed out of the base material band, and holes 4a to 4d are formed at the same time. Thereafter, as described above, the non-magnetic metal plates 3, 3 'are provided on both sides of the magnetic metal plate 1.
Are laminated, and the protrusions 2a to 2d are inserted into the holes 4a to 4d, and the protrusions 2a to 2d
The portions protruding from the holes 4a to 4d are crimped against the peripheral portions of the holes 4a to 4d by pressing, and the nonmagnetic metal plates 3, 3 'are joined to the magnetic metal plate 1 to complete the shield plate.

As described above, since the manufacturing process of the magnetic head shield plate of the present embodiment is a press, the entire process is performed by a progressive press machine that has a plurality of pressing stations and sequentially presses each station. Automatically and consistently. Therefore, the magnetic head shield plate can be mass-produced with extremely high productivity and can be manufactured at low cost. In this case, since the dimensional accuracy of the shield plate is determined by the accuracy of each part such as a press die of the press machine, the shield plate can be easily manufactured with high dimensional accuracy and high yield by selecting the press machine.

Further, the method of joining the magnetic metal plate 1 and the non-magnetic metal plates 3, 3 'by caulking the above-mentioned protrusions 2a to 2d of the present embodiment is different from the conventional joining method by press-fitting the bosses. Since the swaged portion engages with the edges of the holes 4a to 4d, a remarkably large bonding strength can be obtained. Further, it is possible to prevent occurrence of defects such as peeling of the shield plate for the magnetic head.

In the above description, a magnetic head shield plate is formed by laminating and joining three metal plates.
It may be configured by laminating and joining two or more metal plates. In this case, the same effect as described above can be obtained by applying the above-described bonding method.

[Effects of the Invention] As is apparent from the above description, according to the present invention, in a magnetic head shield plate formed by laminating and joining a plurality of metal plates each having a predetermined shape, and a method of manufacturing the same, At least one of the plurality of metal plates has a bottomless cylindrical protrusion (by burring) longer than the thickness of the other metal plate. A hole is formed in a corresponding portion, and the convex portion is inserted into the hole, and the metal plate is joined by caulking against a peripheral portion of the hole. An excellent effect is obtained that a high-quality magnetic head shield plate having no defect and high dimensional accuracy can be manufactured at high yield with good productivity at low cost.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view for explaining a structure and a manufacturing method of a magnetic head shield plate according to an embodiment of the present invention, FIG. 2 is a perspective view of the shield plate in a completed state, and FIG. 3 is a conventional shield plate. It is a perspective view which shows the structure of. 1: magnetic metal plate 2a-2d: convex portion (burring portion) 3, 3 ': non-magnetic metal plate 4a-4d: hole

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G11B 5/11-5/115

Claims (2)

(57) [Claims] 1. A magnetic head shield plate formed by laminating and joining a plurality of metal plates each having a predetermined shape, wherein at least one of the plurality of metal plates includes another metal plate. Forming a bottomless cylindrical protrusion that is longer than the thickness of the plate, forming a hole in a portion corresponding to the protrusion on the other metal plate, inserting the protrusion into the hole, and forming a peripheral edge of the hole. A shield plate for a magnetic head, characterized in that the metal plates are joined together by caulking a portion. 2. A method of manufacturing a shield plate for a magnetic head, wherein a plurality of metal plates each formed in a predetermined shape are laminated and bonded, wherein at least one of the plurality of metal plates is provided. Forming a non-bottom cylindrical protrusion longer than the thickness of the other metal plate by burring, forming a hole in a portion corresponding to the protrusion with respect to the other metal plate, A method for manufacturing a shield plate for a magnetic head, comprising a step of joining the metal plates by inserting a portion into the hole and caulking the peripheral portion of the hole.